Certified Welder Heat Input and Distortion Control

Question 1

What is the correct formula for calculating heat input in welding?

Accepted Answer

(Amps × Volts × 60) / Travel Speed (in/min)

Answer

Heat input is calculated as (Amps × Volts × 60) / Travel Speed, expressed in joules per inch, representing total energy deposited per unit length.

Question 2

What effect does increasing travel speed have on heat input when amperage and voltage remain constant?

Accepted Answer

Decreases heat input

Answer

Increasing travel speed reduces the time the arc dwells over a given area, depositing less energy per inch and thereby decreasing heat input.

Question 3

Which type of distortion causes the ends of a welded plate to bow upward along its length?

Accepted Answer

Longitudinal bowing (camber)

Answer

Longitudinal bowing (camber) causes the ends of a welded plate to curve upward due to differential shrinkage along the long axis of the weld.

Question 4

What is the primary purpose of preheating base metal before welding?

Accepted Answer

To reduce the risk of hydrogen-induced cracking by slowing the cooling rate

Answer

Preheating slows the cooling rate, allowing diffusible hydrogen to escape from the weld zone and reducing the risk of hydrogen-induced (cold) cracking.

Question 5

What does interpass temperature refer to in a multi-pass weld?

Accepted Answer

The temperature of the weld bead before the next pass is deposited

Answer

Interpass temperature is the temperature of the previously deposited weld bead or base metal adjacent to the weld before the next pass is applied, and must be kept within specified limits.

Certified Welder Practice Test

Certified Welder Practice Test

Certified Welder Heat Input and Distortion Control